Andrea Bargnani’s elbow injury could sideline him for another significant chunk of time.The Raptors centre will undergo diagnostic testing on his elbow Monday after he aggravated it during Friday night’s 118-116 overtime loss to the Lakers in Los Angeles.Bargnani missed 26 games earlier this season when he tore ligaments in his right elbow and sprained his right wrist Dec. 10 at Portland.The Raptors also rested Rudy Gay on Sunday. Gay has been struggling with stiffness in his back.Toronto coach Dwane Casey said Bargnani was injured when he got wedged on a pick-and-roll coverage.Casey said if Bargnani’s injury is long-term the team will “definitely have to” bring back forward Quincy Acy from Bakersfield of the NBA D-League.